A kind of silicon nitride single crystal and its preparation method and application

Abstract

The invention discloses a silicon nitride single crystal, its preparation method and application. The preparation method includes: using epitaxial growth method to directly epitaxially grow multilayer graphene as an insertion layer on a SiC substrate to obtain a graphene / SiC substrate; and, placing the graphene / SiC substrate on In the reaction chamber of the epitaxial growth equipment, a gaseous nitrogen source is introduced into the reaction chamber for epitaxial growth, thereby producing a silicon nitride single crystal. The method for preparing silicon nitride single crystals in the present invention does not need to add additional silicon sources, the steps are simple, the operation is safe, and can be peeled off and transferred together with graphene; at the same time, the silicon nitride single crystal particles prepared by the present invention have high uniformity and good quality. The residual stress is small.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a silicon nitride single crystal and its preparation method and application. Background technique [0002] Silicon nitride material has excellent high temperature performance, such as high strength, high hardness, good wear resistance, thermal shock resistance and oxidation resistance, and also has corrosion resistance and high chemical stability. It is widely used in metallurgical refractory, Aerospace and ceramic composite materials. And similar to III-N compounds such as GaN and AlN, silicon nitride is also a wide-bandgap semiconductor (5.3eV) with a high doping level, and its electrical and electronic properties can be adjusted by reducing its energy band by doping and other means. Optical properties, so as to prepare electronic devices that can be used in high temperature and high radiation environments. [0003] Nanostructures have the characteristics o...

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Problems solved by technology

[0005] There are still various deficiencies in the preparation of silicon nitride at present. For example, patent CN104891455A discloses a method for preparing silicon nitride nanomaterials, which is mainly by placing a mixture of silicon tetrachloride and lithium nitride in a special stainless steel reactor and Sealed, heated in a resistance crucible furnace, the product is washed with alcohol, pickled and water until neutral, separated and dried to obtain silicon nitride nanomaterials, but this method uses silicon tetrachloride as raw material to prepare silicon nitride, tetrachloride Silicon is very harmful to the human body and is likely to cause environmental pollution; Yang et al. (Ultra-Long Single-Crystalline Alpha-Si 3 N 4 Nanowires: Derived Froma Polymeric Precursor [J]. Journal of the American Ceramic Society, 2005, 88 (6): 1647-1650) uses liquid polysilazane as a raw material, which is first cured at 260°C, then taken out and ground and mixed with FeCl 2 Mix well and react under nitrogen at 1250°C to obtain single crystal nanowires of good quality. However, in comparison experiments, it was found that no nanowires would be formed without the addition of catalysts, and metal elements were introduced as catalysts. The purity of silicon nitride was low, which caused great harm to purification. Difficulty, complicated process; Lin et al. (Synthesis and optical property of ultra-long alpha-Si 3 N 4 nanowires under superatmospheric pressure conditions[J]. Crystengcomm, 2012, 14(9): 3250-3256) with methane as reducing gas, nitrogen as nitrogen source, SiO or Si and SiO 2 The mixed substance is used as the silicon source, nitrogen and argon are used as the carrier gas, and high-quality silicon nitride nanowires are grown by CVD under the conditions of pressurization (1.1-1.5atm) and 1400-1550°C, but this method contains methane and other flammable materials. Gas, harsh reaction conditions, such as high temperature of 1500 ° C, need to pressurize, etc., resulting in low operating safety and high requirements for equipment; patent CN108059133A discloses a nano-silicon nitride and its preparation method, which is to process silicate Ball milling to obtain powdered silicate, and mix it with magnesium powder, magnesium chloride, and ammonium chloride to obtain a mixture, and then heat the obtained mixture to 800-1000°C at a heating rate of 8-20°C / min and keep it for 6 ~18h, pickling after cooling to obtain nano-silicon nitride, but the nano-silicon nitride particles prepared by ball milling method are not uniform

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